The subject matter disclosed herein relates to a method of determining a common coordinate system for a plurality of coordinate measurement devices and in particular to a method of determining a common coordinate system between a portable articulated arm coordinate measurement machine (AACMM) and a scanner.
A coordinate measurement device is a device that may be used by an operator to measure and electronically capture coordinates of points on a surface. There are several different types of coordinate measurement devices, such as but not limited to: an AACMM, a laser line probe, a laser tracker and an optical structured light scanner for example. The coordinates of the measured points are determined relative to a local coordinate reference system of the measurement device. For example, the AACMM may have a local coordinate system positioned in the base of the device. The local coordinate reference system allows each of the measurements made by the measurement device to be taken relative to each other. The coordinate reference system may be made during post processing.
It should be appreciated that it is difficult to use different types of coordinate measurement devices together to measure a single object or environment since each device acquires the coordinate data in a different coordinate frame. Further complicating this problem is that different types of coordinate measurement machines use different techniques for calibration and registration. For example, optical systems may use circular adhesive photogrammetry labels for registration. However, it would be difficult for an AACMM with a contact-type probe to measure these labels with a desired level of accuracy.
Accordingly, while existing systems for measuring coordinates of points on a surface are suitable for their intended purposes the need for improvement remains, particularly in providing a common coordinate reference frame for a pair of coordinate measurement devices that are operated independent of each other to measure an object.